KR20210102363A - Polymerizable Liquid Crystal Ink Formulations - Google Patents

Abstract

The present invention is a polymerizable liquid crystal formulation; and in particular 10 to 50% by weight of at least one polymerizable liquid crystal compound, and 50 to 90% by weight of one selected from the group consisting of aliphatic ketones, cyclic ketones, alkyl ethers of ethylene glycol or propylene glycol, alkyl esters of menthyl or aromatic solvents. It relates to an ink formulation for inkjet printing comprising the above organic solvent.

Description

Polymerizable Liquid Crystal Ink Formulations

The present invention is a polymerizable liquid crystal formulation; and in particular 10 to 50% by weight of at least one polymerizable liquid crystal compound, and 50 to 90% by weight of one selected from the group consisting of aliphatic ketones, cyclic ketones, alkyl ethers of ethylene glycol or propylene glycol, alkyl esters of menthyl or aromatic solvents. It relates to an ink formulation for inkjet printing comprising the above organic solvent.

The flat liquid crystal display exhibits good image quality, low cost and good processability over a large area size due to a stable supply chain of all its parts. However, luminance and color gamut are generally inferior compared to light emitting diodes (LEDs) and organic light emitting diode displays (OLEDs). The larger layout including polarizers, absorptive color filters and optical films present in LCD panels compared to OLED panels is a major contributor to the lower transmittance and color purity of LCD displays, which results in less energy efficient devices. For reference, only about 30% of the light emitted from the backlight unit is experienced by the user, because the light is blocked or absorbed by the liquid crystal panel.

JP 4752581 B2 proposes an improved method for manufacturing a color filter, which includes a process of forming a barrier on a substrate; forming a multicolor pixel pattern with a predetermined delay between the barriers by photolithography; forming an alignment film on the color pixel pattern by alignment treatment; and forming a liquid crystal phase shifting layer on the alignment film by an inkjet method by matching each delay of the multicolor pixel pattern, wherein the liquid crystal phase shifting layer has a plurality of liquid crystal phase shifting regions corresponding to the multicolor pattern. comprising; the plurality of liquid crystal phase shifting regions have a delay correcting delay of the multicolor pixel pattern; The sum of the delay for the multicolor pixel pattern and the delay of the corresponding plurality of liquid crystal phase shifting regions is characteristically essentially the same for each pixel.

However, the proposed process typically requires additional processing steps in terms of known mass production methods, such as forming the barrier on the substrate by photolithography.

Another attempt to improve lighting efficiency has been reported as a colorless filter LCD panel. Such a display has a backlight unit comprising a plurality of white, red, green and blue light emitting diodes arranged on a substrate, for example described in US Pat. No. 8,928, 841 B2.

A phosphor-converted white LED comprising a backlight unit emitting blue light which is converted by the phosphor to yellow radiation to provide a final white light is described, for example, in KR 10-0946015 B1.

However, the wide bandwidth for the converted yellow light causes significant limitations in preventing high luminance and color gamut due to absorption of light by the color filter. Therefore, a narrow bandwidth RGB emitter is a desirable option for increasing color reproduction and increasing the overall brightness of LCD displays by avoiding parallax effects.

In this regard, quantum materials (QMs) are perfectly suited to solve the above-mentioned shortcomings due to their excellent properties:

- its central emission wavelength can be tuned by controlling the size of the nanoparticles;

- its FWHM is about 20 to 30 nm, which is mainly determined by its size;

- its photoluminescence efficiency is high;

- The created device arrangement is simple.

On the one hand, these properties make them suitable candidates to replace phosphors in backlight units, which are described, for example, in Adv. Mater. 2010, vol. 22, pp. 3076-3080], on the other hand, these properties also make it a suitable candidate for replacing conventional absorptive color filters, which are described for example in CN 102944943 B. Both approaches result in LCD displays with high transmittance and color gamut, which results in excellent image quality when the color of light is provided as needed for conversion.

Polymeric liquid crystal based optical films or such as optical retarders, brightness enhancing films or reflective optical films are described, for example, in EP 0 940 707 B1, EP 0 888 565 B1 and GB 2 329 393 B1. Its high birefringence, favorable alignment control and stable handling in mass production make it an excellent material for improving the performance of displays.

A commonly used method for mass production of these films comprises the following steps:

- providing a continuous layer of polymerizable LC material to the substrate, for example by inkjet printing;

- polymerizing the polymerizable component of the polymerizable LC material by photopolymerization, and

- optionally removing the polymerized LC material from the substrate and/or optionally providing it to another substrate.

Due to the procedure described above, the polymerizable liquid crystal or reactive mesogen (RM) based optical film forms a continuous film that is provided as a single layer in the display layout with different thicknesses across the entire layer.

The optical retardation (δ(λ)) of this polymer film as a function of the wavelength (λ) of the incident beam is given by the following equation:

δ(λ) = (2πΔn d)/λ

where Δn is the birefringence of the film, d is the thickness of the film, and λ is the wavelength of the incident beam.

Therefore, the optical retardation of a given polymerized liquid crystal film is constant in the x-y plane. However, ideally for all subpixels (RGB), different optical performance in the x-y plane of the polymer film is needed for each color. In addition, cholesteric optical films are often used to enhance the brightness of devices, but also different optical reflections of the polymer film are required for each color.

Inkjet printing is a manufacturing technique that deposits inks or materials onto a variety of substrates with micron-scale precision, such as sub-pixel size. It can be used to create complex patterns that could otherwise be manufactured only through a more complex multi-step process using a photomask, such as a patterned retarder. It also offers the possibility to digitize the manufacturing process, which is currently limited to processes such as roll-to-roll large area substrates. Inkjet printing can also be used to coat specific locations on a given substrate or enables pixel-to-pixel printing.

One common problem with inkjet printing is, for example, in J. Sun, B. Bao, M. He, H. Zhou and Y. Song, ACS Appl. Mater. Interfaces, 2015, 7, 28086-28099 or P. Calvert, Chem. Mater., 2001, 13, 3299 - 3305, control of the thickness profile of dry deposition.

A typical profile observed when inkjet printing solids from solvents is the coffee-ring effect, which is further described in D. Mampallil and H. B. Eral, Adv. Colloid Interface Sci., 2018, 252, 38-54]; [W. Han and Z. Lin, Angew. Chemie - Int. Ed., 2012, 51, 1534-1546] or [R. D. Deegan, O. Bakajin, T. F. Dupont, G. Huber, S. R. Nagel and T. A. Witten, Nature, 1997, 389, 827-829.

The solvent is then depleted at the edges, and the solvent in the center of the dry droplet moves to the edges. These solvents are used together with the solute, leaving the profile upon complete evaporation and material accumulating at the edges.

For non-polymerizable liquid crystal formulations, such as printing inks for OLED applications, see, for example, T. Still, P. J. Yunker and A. G. Yodh, Langmuir, 2012, 28, 4984-4988] or [C. Jiang, Z. Zhong, B. Liu, Z. He, J. Zou, L. Wang, J. Wang, J. Peng and Y. Cao, ACS Appl. Mater. Interfaces, 2016, 8, 26162-26168, methods are described to address the problem of the coffee ring effect, such as the use of mixed solvent systems and surfactants. In addition to these solutions, reducing the evaporation rate to prevent unwanted movement of the solute is described in D. Soltman and V. Subramanian, Langmuir, 2008, 24, 2224-2231].

However, from the standpoint of polymerizable liquid crystal formulations, a smooth surface profile and high alignment quality of liquid crystal molecules are required to produce good optical performance from inkjet printed optical films. In addition, solvent systems used in inks and commonly used for non-polymerizable liquid crystal formulations based on high boiling solvents (such as gamma-butyrolactone, cyclohexyl benzene, butyl benzoate, methyl benzoate, 1-methyl naphthalene) etc.) are not suitable for use with polymerizable liquid crystal mixtures due to the very long time required for their evaporation. Such long evaporation times generally result in poor alignment quality of inkjet printed polymer films obtained from polymerizable liquid crystal formulations.

In addition, conventional solvents used in polymerizable liquid crystal mixtures (such as cyclohexanone, toluene, cyclopentanone, PGMEA, MIBK, etc.) are used in inkjet printing techniques due to the very rapid evaporation of the solvent which prevents the use of inkjet printing techniques. not fit to be Typically, the low boiling solvents described above are not suitable for inkjet printing because the volume of each droplet is much smaller than the standard coating volume. This causes evaporation and subsequent crystallization on the print head, blocking further printing.

With these issues in mind, a polymerizable liquid crystal based on a high boiling solvent system comprising, in addition to one or more polymerizable liquid crystal compounds, preferably one or more solvents for inkjet printing applications, exhibiting a low evaporation rate and a high annealing temperature. There is a great demand for mixtures or ink formulations. In addition, polymer films obtained from such formulations by inkjet printing should exhibit good alignment quality after polymerization, even when printed on small areas, such as typically in pixel or subpixel size.

Surprisingly, the inventors have found that certain families of solvents, and solvent combinations in combination with polymerizable liquid crystal materials, exhibit very good jetting properties while simultaneously achieving high resolution and flat printing profiles.

Accordingly, the present invention provides 10 to 50% by weight of at least one polymerizable liquid crystal compound and 50 to 90% by weight selected from the group consisting of aliphatic ketones, cyclic ketones, alkyl ethers of ethylene glycol or propylene glycol, alkyl esters of menthyl or aromatic solvents. % of one or more organic solvents.

In addition, the present invention provides at least 10 to 50% by weight of at least one polymerizable liquid crystal compound, 50 to 90% by weight of at least one selected from the group consisting of aliphatic ketones, cyclic ketones, alkyl ethers of ethylene glycol or propylene glycol, or aromatic solvents. It relates to a method for preparing an ink formulation by mixing with a solvent.

The invention also relates to the use of the ink formulations described above and below in inkjet printers.

The present invention also relates to a polymer film obtainable or obtainable by inkjet printing the ink formulations described above and below on a substrate and curing said ink formulations.

The present invention also relates to a method for producing a polymer film comprising the steps of inkjet printing the ink formulations described above and below on a substrate, and curing the ink formulations.

The invention also relates to the use of the polymer films described above and below as optical films or in optical components.

The present invention also relates to an optical component comprising at least one polymer film obtainable or obtained from the ink formulations described above and below.

Another aspect of the invention is the use of one or more optical components as described above and below in optical devices.

Another aspect of the present invention is an optical device comprising at least one optical component comprising at least one polymer film obtainable or obtained from at least one of the ink formulations described above and below.

The present invention provides 10 to 50% by weight of at least one polymerizable liquid crystal compound, and 50 to 90% by weight selected from the group consisting of an aliphatic ketone, a cyclic ketone, an alkyl ether of ethylene glycol or propylene glycol, an alkyl ester of menthyl or an aromatic solvent. A polymerizable liquid crystal ink formulation for inkjet printing comprising at least one organic solvent.

Preferably, the at least one polymerizable liquid crystal compound used in the ink formulation according to the present invention is selected from direactive or polyreactive compounds of the formula DRM:

In the above formula,

P ¹ and P ² are independently of each other a polymerizable group,

Sp ¹ and Sp ² are independently of each other a spacer group or a single bond,

MG is a rod-shaped mesogenic group, which is preferably selected from the formula MG:

,

,

A ¹ and A ^2, in the case of multiple occurrences, independently of each other, are aromatic or cycloaliphatic groups, which optionally contain one or more heteroatoms selected from N, O and S, optionally mono- or polysubstituted ^{with L 1 ,}

L ¹ is P-Sp-, F, Cl, Br, I, -CN _{, -NO 2} , -NCO, -NCS, -OCN, -SCN, -C(=O)NR ⁰⁰ R ⁰⁰⁰ , -C(= O)OR ⁰⁰ , -C(=O)R ⁰⁰ , -NR ⁰⁰ R ⁰⁰⁰ , -OH, -SF ₅ , optionally substituted silyl, aryl having 1 to 12, preferably 1 to 6 C atoms or heteroaryl, or straight or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12, preferably 1 to 6 C atoms, wherein one or more H atoms are optionally substituted with F or Cl,

R ⁰⁰ and R ⁰⁰⁰ are independently of each other H or alkyl having 1 to 12 C atoms,

Z ¹ is independently of each other in the case of multiple occurrences, -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, - CO-NR ⁰⁰ -, -NR ⁰⁰ -CO-, -NR ⁰⁰ -CO-NR ⁰⁰⁰ , -NR ⁰⁰ -CO-O-, -O-CO-NR ⁰⁰ -, -OCH ₂ -, -CH ₂ O- , -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CH ₂ CH ₂ -, -(CH ₂ ) _n1 , -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CF ₂ CF ₂ -, -CH=N-, -N=CH-, -N=N-, -CH=CR ⁰⁰ -, -CY ¹ =CY ² -, -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,

Y ¹ and Y ² are each independently H, F, Cl or CN,

n is 1, 2, 3 or 4, preferably 1 or 2, most preferably 2,

n1 is an integer of 1 to 10, preferably 1, 2, 3 or 4.

The "polymerizable group" (P) is preferably selected from the group consisting of groups containing a C=C double bond or a C≡C triple bond, and groups suitable for polymerization by ring opening, such as oxetane or epoxide groups.

, CH₂=CW²-(O)_k3-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-CO-NH-, CH₃-CH=CH-O-, (CH₂=CH)₂CH-OCO-, (CH₂=CH-CH₂)₂CH-OCO-, (CH₂=CH)₂CH-O-, (CH₂=CH-CH₂)₂N-, (CH₂=CH-CH₂)₂N-CO-, CH₂=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2- 및 Phe-CH=CH-로 이루어진 군으로부터 선택되고, 여기서Preferably, the polymerizable group (P) is CH ₂ =CW ¹ -COO-, CH ₂ =CW ¹ -CO-,

, CH ₂ =CW ² -(O) _k3 -, CW ¹ =CH-CO-(O) _k3 -, CW ¹ =CH-CO-NH-, CH ₂ =CW ¹ -CO-NH-, CH ₃ - CH=CH-O-, (CH ₂ =CH) ₂ CH-OCO-, (CH ₂ =CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ =CH) ₂ CH-O-, (CH ₂ = CH-CH ₂ ) ₂ N-, (CH ₂ =CH-CH ₂ ) ₂ N-CO-, CH ₂ =CW ¹ -CO-NH-, CH ₂ =CH-(COO) _k1 -Phe-(O) _{selected from the group consisting of k2} -, CH ₂ =CH-(CO) _k1 -Phe-(O) _k2 - and Phe-CH=CH-, wherein

W ¹ is H, F, Cl, CN, CF ₃ , phenyl, or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH ₃ , W ² is H, or 1 to 5 C atoms is alkyl, in particular H, methyl, ethyl or n-propyl, W ³ and W ⁴ are each independently H, Cl, or alkyl having 1 to 5 C atoms, and Phe is 1,4-phenylene , which is optionally substituted with one or more radicals L as defined above which are not P-Sp, preferably preferred substituents L are F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ or phenyl, and k1, k2 and k3 are each independently 0 or 1 , k3 is preferably 1, and k4 is an integer from 1 to 10.

이고, 여기서 W²는 H, 또는 1 내지 5개의 C 원자를 갖는 알킬, 특히 H, 메틸, 에틸 또는 n-프로필이다.Particularly preferred polymerisable groups P are CH ₂ =CH-COO-, CH ₂ =C(CH ₃ )-COO-, CH ₂ =CF-COO-, CH ₂ =CH-, CH ₂ =CH-O-, ( CH ₂ =CH) ₂ CH-OCO-, (CH ₂ =CH) ₂ CH-O-,

wherein W ² is H, or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl.

Further preferred polymerisable groups (P) are vinyloxy, acrylates, methacrylates, fluoroacrylates, chloroacrylates, oxetanes or epoxides, most preferably acrylates or methacrylates, especially acrylates .

Preferably, all polyreactive polymerizable compounds and compounds of the sub-formulae thereof have, instead of at least one radical P-Sp-, at least two polymerizable groups P containing at least one branched radical (polyreactive polymerizable radicals) contains

Suitable radicals of this type, and polymerisable compounds containing them, are described, for example, in US Pat. No. 7,060,200 B1 or US 2006/0172090 A1.

Particular preference is given to polyreactive polymerizable radicals selected from the formula:

In the above formula,

Alkyl is a single bond, or straight-chain or branched alkylene having 1 to 12 C atoms, wherein one or more non-adjacent CH ₂ groups are, independently of each other, —C( R ^x )=C(R ^x )-, -C≡C-, -N(R ^x )-, -O-, -S-, -CO-, -CO-O-, -O-CO- or - each may be replaced by O—CO—O—, wherein one or more H atoms may also be replaced by F, Cl or CN, wherein R ^x has one of the preceding meanings,

_aa and _bb are each independently 0, 1, 2, 3, 4, 5 or 6,

X has one of the meanings given for X';

P ^v to P ^z each independently of one another has one of the meanings given above for P.

Preferred spacer groups Sp are selected from the formula Sp'-X', such that the radical "P-Sp-" conforms to the formula "P-Sp'-X'-", wherein

Sp' is alkylene having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or polysubstituted with F, Cl, Br, I or CN, wherein also one or more non-adjacent C atoms CH ₂ groups are, independently of each other, -O-, -S-, -NH-, -NR ^xx -, -SiR ^xx R ^yy -, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, -NR ^xx -CO-O-, -O-CO-NR ^0xx -, -NR ^xx -CO-NR ^yy -, -CH=CH- or -C≡C- can be replaced respectively,

X' is -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ^xx -, -NR ^xx -CO-, -NR ^xx -CO-NR ^yy -, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CF ₂ CF ₂ -, -CH=N-, -N=CH-, -N=N-, -CH=CR ^xx -, -CY ^xx =CY ^xx - , -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,

R ^xx and R ^yy are each independently of one another H, or alkyl having 1 to 12 C atoms,

Y ^xx and Y ^yy are each independently H, F, Cl or CN.

X' is preferably -O-, -S- -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ^xx -, -NR ^xx -CO-, -NR ^xx -CO -NR ^yy - or a single bond.

A typical spacer group Sp' is for example -(CH ₂ ) _p1 -, -(CH ₂ CH ₂ O) _q1 -CH ₂ CH ₂ -, -CH ₂ CH ₂ -S-CH ₂ CH ₂ -, -CH ₂ CH ₂ -NH-CH ₂ CH ₂ - or -(SiR ^xx R ^yy -O) _p1 -, wherein p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, R ^xx and R ^yy are has a meaning

A particularly preferred group -X'-Sp'- is -(CH ₂ ) _p1 -, -O-(CH ₂ ) _p1 -, -OCO-(CH ₂ ) _p1 - or -OCOO-(CH ₂ ) _p1 -, Here, p1 is an integer from 1 to 12.

Particularly preferred groups Sp' are, for example, in each case straight-chain, methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octade silane, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene or butenylene.

Preferred groups A ¹ and A ² are, but are not limited to, furan, pyrrole, thiophene, oxazole, thiazole, thiadiazole, imidazole, phenylene, cyclohexylene, bicyclooctylene, cyclohexenylene, pyridine, pyridine midine, pyrazine, azulene, indane, fluorene, naphthalene, tetrahydronaphthalene, anthracene, phenanthracene and dienothiophene, all of which are unsubstituted or 1, 2, 3 or 4 as defined above. substituted with a group L.

Particularly preferred groups A ¹ and A ² are 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, thiophene-2,5-diyl, naphthalene-2,6 -diyl, 1,2,3,4-tetrahydro-naphthalene-2,6-diyl, indane-2,5-diyl, bicyclooctylene or 1,4-cyclohexylene, wherein One or more non-adjacent CH ₂ groups are optionally replaced with O and/or S, wherein said groups are unsubstituted or substituted with 1, 2, 3 or 4 groups L as defined above.

Particularly preferred groups Z ¹ in each case independently of one another are preferably -COO-, -OCO-, -CH ₂ CH ₂ -, -CF ₂ O-, -OCF ₂ -, -C≡C-, -CH= CH-, -OCO-CH=CH-, -CH=CH-COO- or a single bond.

Highly preferred direactive mesogenic compounds of formula DRM are selected from the formula:

In the above formula,

P ⁰ in the case of multiple occurrences, independently of each other, are polymerizable groups, preferably acrylic, methacryl, oxetane, epoxy, vinyl, heptadiene, vinyloxy, propenyl ether or styrene groups,

L in each occurrence, identically or differently ^{, has one of the meanings given for L 1} in the formula DRM, preferably, in the case of multiple occurrences, independently of each other F, Cl, CN, or optionally having 1 to 5 C atoms is halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy,

r is 0, 1, 2, 3 or 4,

x and y are each independently 0, or an integer from 1 to 12 that is the same or different,

z is each independently 0 or 1, provided that when adjacent x or y is 0, z is 0.

Particular preference is given to compounds of the formulas DRMa1, DRMa2 and DRMa3, in particular compounds of the formula DRMa1.

Still preferably, the at least one polymerizable compound used in the ink formulation according to the invention is selected from monoreactive liquid crystal compounds of the formula MRM:

In the above formula,

P ¹ , Sp ¹ and MG have the meanings given in formula DRM,

R is F, Cl, Br, I, -CN, _{-NO 2} , -NCO, -NCS, -OCN, -SCN, -C(=O)NR ^x R ^y , -C(=O)X, -C (=O)OR ^x , -C(=O)R ^y , -NR ^x R ^y , -OH, -SF ₅ , optionally substituted silyl, 1 to 12, preferably 1 to 6 C atoms; straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, wherein one or more H atoms are optionally substituted with F or Cl;

X is halogen, preferably F or Cl,

R ^x and R ^y are independently of each other H or alkyl having 1 to 12 C atoms.

Preferred monoreactive mesogenic compounds of formula MRM are selected from the formula:

In the above formula,

P ⁰ , L, r, x, y and z are as defined in formula DRMa-1 to formula DRMe,

R ⁰ is alkyl, alkoxy, thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 or more, preferably 1 to 15 C atoms, or Y ⁰ ,

Y ⁰ is F, Cl, CN, NO ₂ , OCH ₃ , OCN, SCN, SF ₅ , or monofluorinated, oligofluorinated or polyfluorinated alkyl or alkoxy having 1 to 4 C atoms,

Z ⁰ is -COO-, -OCO-, -CH ₂ CH ₂ -, -CF ₂ O-, -OCF ₂ -, -CH=CH-, -OCO-CH=CH-, -CH=CH-COO- or a single bond,

A ⁰ is, independently of each other in the case of multiple occurrences, 1,4-phenylene unsubstituted or substituted with 1, 2, 3 or 4 groups L, or trans-1,4-cyclohexylene,

u and v are independently of each other 0, 1 or 2,

w is 0 or 1,

The benzene and naphthalene rings may be further substituted with one or more identical or different groups L.

Further preference is given to compounds of the formulas MRM1, MRM2, MRM3, MRM4, MRM5, MRM6, MRM7, MRM9 and MRM10, in particular compounds of the formulas MRM1, MRM4, MRM6 and MRM7, in particular compounds of the formulas MRM1 and MRM7.

Compounds of the formulas DRM, MRM, and their subformulae are known to those skilled in the art and described in standard work in organic chemistry, such as Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart. It can be prepared similarly to the method.

The compounds of the formulas DRM, MRM and their sub-formulae may preferably be used alone or in combination with each other.

Preferably, the polymerizable liquid crystal compound used comprises at least one compound of formula DRM, more preferably at least one compound of formula DRM and at least one compound selected from compounds of formula MRM.

The ratio of the compounds of the formulas DRM, MRM and their sub-formulae is preferably in the range of 30 to 99.9% by weight, more preferably in the range of 40 to 99.9% by weight, even more preferably in the range of 30 to 99.9% by weight, based on the total polymerizable liquid crystal compound used. 50 to 99.9% by weight.

In a preferred embodiment, the proportion of the direactive polymerizable mesogenic compound is preferably in the range from 5 to 99% by weight, more preferably in the range from 10 to 97% by weight, even more preferably in the range of from 5 to 99% by weight, based on the polymerizable liquid crystal compound used. 15 to 95% by weight.

In another preferred embodiment, the proportion of monoreactive polymerizable mesogenic compound, if present, is preferably in the range of 5 to 80% by weight, more preferably in the range of 10 to 75% by weight, based on the polymerizable liquid crystal compound used. range, even more preferably in the range from 15 to 70% by weight.

In another preferred embodiment, the proportion of the polyreactive polymerizable mesogenic compound in the total polymerizable liquid crystal material according to the invention, if present, is preferably in the range from 1 to 30% by weight, more preferably from 2 to 20% by weight. % range, even more preferably in the range from 3 to 10% by weight.

In another preferred embodiment, the polymerizable LC material does not contain polymerizable mesogenic compounds having more than two polymerizable groups.

In another preferred embodiment, the polymerizable LC material does not contain polymerizable mesogenic compounds having less than two polymerizable groups.

Preferably at least one organic solvent, preferably all selected solvents are selected from solvents having a boiling point in the range from 60°C to 380°C, preferably in the range from 100°C to 340°C, most preferably in the range from 120°C to 330°C .

Preferably at least one organic solvent, preferably all selected solvents, are selected from solvents having a melting point, preferably less than 25° C., meaning that the selected solvent is liquid at room temperature.

Preferably at least one organic solvent, preferably all selected solvents, are selected from solvents having a viscosity of greater than 15 mPas, preferably greater than 20 mPas, more preferably greater than 25 mPas and most preferably greater than 50 mPas.

Preferably at least one organic solvent, preferably all selected solvents, are selected from solvents such that the polymerizable liquid crystal compound used exhibits a solubility of at least 5 g/l, preferably at least 10 g/l in the selected solvent. .

Examples of preferred organic solvents and their boiling points (BP) and melting points (MP) are shown in Table 1 below.

Preferred organic solvent systems or mixtures are combinations of cyclohexanone: di(propylene glycol) methyl ether acetate, cyclohexanone: propylene glycol monomethyl ether acetate, or di(propylene glycol) methyl ether acetate: propylene glycol monomethyl ether acetate. . A preferred mixture ratio of the organic solvent system is in the range from 2:1 to 1:2.

The formulations of the invention preferably have a viscosity in the range from 0.8 to 50 mPa.s, more preferably in the range from 1 to 40 mPa.s, and most preferably in the range from 2 to 15 mPa.s.

The viscosity of the formulations and solvents according to the invention is measured using a 1° cone-plate rotary rheometer (Thermo Scientific) of type Discovery AR3. The instrument allows precise control of temperature and shear rate. The measurement of the viscosity is carried out at a temperature of 25.0° C. (+/- 0.2° C.) and a shear rate of ^{500 s −1 .} Each sample is measured in triplicate and the measurements obtained are averaged.

The formulations of the present invention preferably have a surface tension in the range from 15 to 70 mN/m, more preferably in the range from 10 to 50 mN/m and most preferably in the range from 20 to 40 mN/m.

Preferably, the organic solvent blend has a surface tension in the range of 15 to 70 mN/m, more preferably in the range of 10 to 50 mN/m and most preferably in the range of 20 to 40 mN/m.

Surface tension can be measured using a First Ten Angstrom (FTA) 1000 contact angle goniometer at 20°C. A detailed method is available from First Ten Angstrom as Roger P. Woodward, Ph.D., "Surface Tension Measurements Using the Drop Shape Method". Preferably, a pendant drop method can be used to determine the surface tension. This measurement technique dispenses a drop from the needle as a bulk liquid or gas phase. The shape of the drop results from the correlation between surface tension, gravity, and density differences. Using the pendant drop method, the surface tension is calculated from the shaded image of the pendant drop using the url [http://www.kruss.de/services/education-theory/glossary/drop-shape-analysis]. All surface tension measurements were performed using a commonly used and commercially available high precision drop shape analysis tool, the FTA1000 from First Ten Angstrom. The surface tension is determined by software FTA1000. All measurements were performed at room temperature ranging from 20°C to 25°C. Standard operating procedures include determination of the surface tension of each formulation using an unused disposable drop dispensing system (syringe and needle). Each drop was measured by 60 measurements over a period of 1 minute and then averaged. Three drops were measured for each formulation. The final values were averaged over these measurements. The tools were regularly cross-checked against a variety of liquids with known surface tensions.

For the preparation of the brightness enhancement film, typically a cholesteric polymerizable liquid crystal ink formulation was used. Accordingly, in a preferred embodiment, the polymerizable liquid crystal ink formulation according to the present invention comprises at least one chiral additive used to induce a cholesteric phase.

Preferred chiral additives can be selected from chiral RMs and chiral dopants, many of which are well known to the skilled artisan and are commercially available.

Suitable non-polymerizable chiral compounds are, for example, chiral dopants such as R- or S-811, R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011, R - or S-5011, or CB 15, all available from Merck KGaA, Darmstadt, Germany.

Suitable polymerizable chiral compounds are, for example, the chiral RMs (R1) to (R10) listed below, or the polymerizable chiral material Paliocolor® LC756 (BASF AG, Ludwigshafen, Germany).

wherein P has one of the meanings defined for ^{P 0 above, Z 0} , u, v, x, y, R ⁰ and A are as defined above, and L ¹ and L ² are each independently has one of the meanings of L given above.

Chiral compounds with high HTP, in particular compounds comprising a sorbitol group as described for example in WO 98/00428, for example a compound comprising a hydrobenzoin group as described in GB 2,328,207, for example a chiral binaf as described in WO 02/94805 tyl derivatives, for example the chiral binaphthol acetal derivatives described in WO 02/34739, for example the chiral TADDOL derivatives described in WO 02/06265, and one or more fluorinated derivatives, for example described in WO 02/06196 or WO 02/06195 Very preferred are chiral compounds having a linking group and a terminal or central chiral group.

Particular preference is given to chiral compounds having an HTP of at least 40 μm ⁻¹ , very preferably at ^{least 60 μm −1} and most preferably at ^{least 80 μm −1 .}

Particular preference is given to polymerizable sorbitols, such as those of the formulas R8 and R9, and polymerizable hydrobenzoins, such as those of the formula R10.

Further preferred are non-polymerizable sorbitols and hydrobenzoins of the formulas M1 and M2 below. Further preferred are chiral binaphthols of the following formulas M3 and M4.

wherein P, Z ⁰ , A, L ¹ , L ² , v and x have the meanings given above, R ^{1 has one of the meanings of R 0} given above or is P-Sp, and R is R ^{has one of the meanings of 0} , m is 0, 1, 2 or 3, and r1 and r2 are 0, 1, 2, 3 or 4.

Very preferred are compounds of formula M3, wherein R ^{1 is P-Sp.} m is 0 or 1, Z ⁰ is -COO-, -OCO- or a single bond, and A is 1,4-phenylene optionally substituted with ^{1 or 2 groups L 1 , or trans-1,4-} Further preference is given to compounds of the formula M3, which are cyclohexylene.

Formulations with chiral additives preferably exhibit a cholesteric LC phase, very preferably a cholesteric LC phase at room temperature.

In a further preferred embodiment, the formulation optionally contains additional polymerization initiators, antioxidants, surfactants, stabilizers, catalysts, sensitizers, inhibitors, chain transfer agents, co-reacting monomers, reactive thinners, surface-active compounds, lubricants, wetting agents , dispersants, hydrophobizing agents, adhesives, flow improvers, degassing agents, defoamers, defoamers, diluents, reactive diluents, adjuvants, colorants, dyes, pigments and nanoparticles.

Lubricants and flow aids typically include silicon-free polymers, as well as silicon-containing polymers such as polyacrylates or modifiers, low molecular weight polydialkylsiloxanes. Modifications may exist in some of the alkyl groups replaced by various organic radicals. These organic radicals are, for example, polyether, polyester or even long-chain (fluorinated) alkyl radicals, the former being most commonly used.

Polyether radicals in correspondingly modified polysiloxanes are generally generated from ethylene oxide and/or propylene oxide units. In general, the higher the ratio of these alkylene oxide units in the modified polysiloxane, the more hydrophilic the resulting product.

Such adjuvants may be obtained from, for example, TEGO® Glide 100, TEGO® Glide ZG 400, TEGO® Glide 406, TEGO® Glide 410, TEGO® Glide 411, TEGO (registered trademark) Glide 415, TEGO (registered trademark) Glide 420, TEGO (registered trademark) Glide 435, TEGO (registered trademark) Glide 440, TEGO (registered trademark) Glide 450, TEGO (registered trademark) Glide A 115, TEGO ( Glide B 1484 (which can also be used as an antifoam or defoamer), TEGO® Flow ATF, TEGO® Flow 300, TEGO® Flow 460, TEGO® Flow 425 and It is commercially available as TEGO® Flow ZFS 460. Suitable radiation-curable lubricants and flow aids, which may also be used to improve scratch resistance, include the products TEGO® Rad 2100, TEGO® Rad 2200, TEGO® Rad 2500, TEGO® Rad 2600 and TEGO® Rad 2700, which are likewise available from TEGO.

Such adjuvants may also be obtained from BYK, for example, BYK(R)-300 BYK(R)-306, BYK(R)-307, BYK(R)-310, BYK(R)-320, BYK(R) Trademarks)-333, BYK (registered trademark)-341, Byk (registered trademark) 354, Byk (registered trademark) 361, Byk (registered trademark) 361N, and BYK (registered trademark) 388 are available.

Such adjuvants are also available, for example, as FC4430® from 3M.

Such adjuvants are also available, for example, as FluorN® 561 or FluorN® 562 from Cytonix.

Such adjuvants are also available, for example, as Tivida(R) FL 2300 and Tivida(R) FL 2500 from Merck KGaA.

These adjuvants are used in a ratio of from about 0 to 3.0% by weight, preferably from about 0 to 2.0% by weight, based on all solids or components, excluding optionally present solvents.

In another preferred embodiment, the formulation comprises one or more specific antioxidant additives, preferably selected from the Irganox® series, for example the antioxidant Irganox® 1076 commercially available from Ciba (Switzerland). and Irganox® 1010.

In another preferred embodiment, the formulation is formulated for example in the commercially available Irgacure® or Darocure® (Ciba AG) series, in particular Irgacure 127, Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 817, Irgacure 907, Irgacure 1300, Irgacure, Irgacure 2022, Irgacure 2100, Irgacure 2959 or Darcure TPO, further commercially available from OXE02 (Ciba AG), NCI 930, N1919T (Adeka), SPI-03 or SPI-04 (Samyang) one or more selected photoinitiators.

The concentration of the total polymerization initiator in the formulation is preferably 0.5 to 10% by weight, very preferably 0.8 to 8% by weight, more preferably 1 to 6% by weight relative to all solids or components excluding solvents present.

Preferably, the ink formulation comprises, in addition to at least one direactive or polyreactive polymerizable mesogenic compound and at least one solvent:

a) at least one monoreactive polymerizable mesogenic compound,

b) one or more photoinitiators,

c) optionally, one or more antioxidant additives;

d) optionally one or more stabilizers;

e) optionally, one or more lubricants and flow aids.

More preferably, the formulation preferably contains at least one, preferably at least two, direactively polymerisable in an amount of from 10 to 90% by weight, very preferably from 15 to 75% by weight, when present with respect to all components except solvent. mesogenic compounds, preferably selected from compounds of formula DRMa-1; and in addition to one or more solvents:

a) optionally, preferably selected from compounds of formula MRM-1 and/or MRM-7, preferably in an amount of from 10 to 95% by weight, very preferably from 25 to 85% by weight relative to all components except for solvents at least one, preferably at least two monoreactive polymerizable mesogenic compounds of

b) optionally, preferably one or more, preferably one photoinitiator, if present, in an amount of from 1 to 10% by weight, very preferably from 2 to 7% by weight, relative to all components except for solvents,

c) optionally, preferably selected from esters of unsubstituted or substituted benzoic acid and, if present, in an amount of preferably from 0.01 to 2% by weight, very preferably from 0.05 to 1% by weight relative to all components except for solvents. one or more antioxidant additives, in particular Irganox® 1076;

d) optionally, preferably selected from TEGO(R) Rad 2500, BYK(R) 388, FC 4430 and/or Fluor N 562, if present, for all components except solvent, preferably 0.1 to at least one lubricant and flow aid in an amount of 5% by weight, very preferably 0.2 to 3% by weight.

In addition, the present invention provides at least 10 to 50% by weight of at least one polyreactive or direactive liquid crystal compound with respect to the total formulation, and 50 to 90% by weight of an aliphatic ketone, a cyclic ketone, an alkyl of ethylene glycol or propylene glycol, based on the entire formulation. A method for preparing an ink formulation by mixing one or more solvents selected from the group consisting of etheric or aromatic solvents.

The invention also relates to the use of the ink formulations described above and below in inkjet printers. Suitable inkjet printers are known to the skilled person and are, for example, the Dimatix(R) Materials Printer series (Fujifilm), for example the DMP-2800 or the PiXDRO(R) LP 50 Meyer Burger.

The present invention also relates to a method for producing a polymer film comprising the steps of inkjet printing the ink formulations described above and below on a substrate, and curing the ink formulations.

The areal thickness of a given layer may vary for various purposes. Typically, the formulation is provided with a thickness in the range of 500 to 2500 nm, preferably in the range of 1000 to 2000 nm, more preferably in the range of 1500 to 1900 nm.

Typically, the area or print dimension provided is in the ^{range of 1 cm 2} to 10 μm ² for use in the color filters described below, preferably the area or print dimension provided corresponds to a sub-pixel size and is typically any The minimum length in pixel shape ranges from 1 to 0.01 mm.

Preferably a suitable drop spacing is selected in the range from 100 to 10 μm, preferably in the range from 50 to 15 μm.

Suitable substrate materials or substrates are known to the expert and described in the literature as conventional substrates used in the optical film industry, such as glass or plastics. Particularly suitable and preferred substrates for polymerization are polyesters such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyvinyl alcohol (PVA), polycarbonate (PC) triacetylcellulose (TAC), cycloolefin polymers (COP). ), or commonly known color filter materials, in particular triacetylcellulose (TAC), cyclo olefin polymers (COP) or commonly known color filter materials.

In a preferred embodiment, the method according to the invention comprises a process step (referred to herein as "annealing") in which the ink formulation is left for a period of time to redistribute the ink evenly to the substrate.

Preferably, after printing, the ink is annealed for 1 minute to 3 hours, preferably 2 minutes to 1 hour, most preferably 5 minutes to 30 minutes. Annealing is preferably carried out at room temperature.

In an alternative embodiment, the annealing is carried out at high temperatures, preferably above 20°C and below 140°C, more preferably above 40°C and below 100°C, most preferably above 50°C and below 90°C.

The polymerizable LC material (RM or reactive mesogen) of the ink formulation preferably exhibits uniform alignment over the entire substrate after curing or crjet printing on the substrate. Preferably the polymerizable LC material exhibits a uniform planar or uniform homeotropic alignment.

By comparing the surface energies of the RM layer and the substrate using the Friedel-Creagh-Kmetz rule, we can predict whether a mixture will adopt a planar or homeotropic alignment:

If γ _RM > γ _s , the reactive mesogenic compound will exhibit homeotropic alignment, and if γ _RM < γ _s , the reactive mesogenic compound will display homogeneous alignment.

When the surface energy of the substrate is relatively low, the intermolecular force between the reactive mesogens is stronger than the force across the RM-substrate interface. Thus, reactive mesogens align perpendicular to the substrate to maximize intermolecular forces (homeotropic alignment).

Also, homeotropic alignment can be achieved by using amphiphiles; It can be added directly to the polymerizable LC material, or the substrate can be treated with these materials in the form of a homeotropic alignment layer. The polar head of the amphipathic material chemically bonds to the substrate, and the carbon tail points perpendicular to the substrate. The intermolecular interaction between the amphiphilic substance and the RM promotes homeotropic alignment. Commonly used amphiphilic surfactants are described above.

Another method used to promote homeotropic alignment is to apply a corona discharge treatment to a plastic substrate to create alcohol or ketone functional groups on the substrate surface. These polar groups interact with polar groups present in the RM or surfactant to promote homeotropic alignment.

When the surface tension of the substrate is greater than that of the RM, the force across the interface is prominent. The interfacial energy is minimized when the reactive mesogen aligns parallel to the substrate so that the long axis of the RM can interact with the substrate. Unidirectional planar alignment can be facilitated by coating the substrate with a polyimide layer and then rubbing the alignment layer with a velvet cloth.

Other suitable planar alignment layers are known in the art and are rubbed polyimide or alignment layers prepared by photoalignment, for example as described in US 5,602,661, US 5,389,698 or US 6,717,644.

In general, reviews of alignment techniques are described, for example, in I. Sage in "Thermotropic Liquid Crystals", edited by G. W. Gray, John Wiley & Sons, 1987, pages 75-77]; and [T. Uchida and H. Seki in "Liquid Crystals - Applications and Uses Vol. 3", edited by B. Bahadur, World Scientific Publishing, Singapore 1992, pages 1-63. Additional reviews of alignment materials and techniques can be found in J. Cognard, Mol. Crystal. Liq. Crystal. 78, Supplement 1 (1981), pages 1-77].

To prepare the polymer film according to the invention, the polymerizable compound of the formulation is cured, polymerized and crosslinked (where one compound contains at least two polymerizable groups).

In a preferred method of preparation, the formulation is printed on a substrate and then photopolymerized, for example by exposure to actinic radiation, as described in WO 01/20394, GB 2,315,072 or WO 98/04651.

Photopolymerization of the formulation is preferably achieved by exposing it to actinic radiation. Actinic radiation means irradiation with light, such as ultraviolet, infrared or visible light, irradiation with X-rays or gamma rays, or irradiation with high-energy particles such as ions or electrons. Preferably, the polymerization is carried out by light irradiation, in particular with ultraviolet light. As the source of actinic radiation, for example, a single ultraviolet lamp or a set of ultraviolet lamps can be used. When using a high lamp power, the curing time can be shortened. Another possible source for light radiation is a laser, for example an ultraviolet laser, an infrared laser or a visible laser.

The curing time depends, inter alia, on the reactivity of the polymerizable LC compound, the thickness of the printed layer, the type of polymerization initiator and the power of the UV lamp.

Typically, the curing time is preferably 5 minutes or less, very preferably 3 minutes or less, and most preferably 1 minute or less. For mass production, short curing times of 30 seconds or less are preferred.

A suitable ultraviolet radiation power is preferably in the range from 5 to 200 mWcm ^-2 , more preferably in the range from 50 to 175 mWcm ^-2 , and most preferably in the range from 100 to 150 mWcm ^-2 .

With respect to the applied ultraviolet radiation, as a function of time, a suitable ultraviolet dose is preferably in the range from 25 to 7200 mJcm ^-2 , more preferably in the range from 500 to 7200 mJcm ^-2 , most preferably in the range from 3000 to 7200 mJcm ^{-2 .} am.

The photopolymerization is preferably carried out under an inert gas atmosphere, preferably in a heated nitrogen atmosphere, but also polymerization in air is possible.

The photopolymerization is preferably carried out at a temperature of 1°C to 70°C, more preferably 5°C to 50°C, even more preferably 15°C to 30°C.

The polymerized LC film according to the invention has good adhesion to plastic substrates, in particular TAC, COP and color filters. Thus, it can be used as an adhesive for subsequent LC layers or as a base coating, which would otherwise not adhere well to the substrate.

For example, the homogeneously homeotropic or planar aligned polymer films of the present invention can be used, for example, as retardation or compensation or reflective films in LCDs to improve contrast and brightness and reduce chromaticity at large viewing angles. It can be used outside of a switchable liquid crystal cell of an LCD, or between substrates, typically glass substrates, to form a switchable liquid crystal cell and to include a switchable liquid crystal medium (in cell applications).

Accordingly, the present invention also relates to the use of the polymer films described above and below as optical films or in optical components.

The optical retardation (δ(λ)) of the polymer film as a function of the wavelength (λ) of the incident beam is given by the following equation:

δ(λ) = (2πΔn d)/λ

where Δn is the birefringence of the film, d is the thickness of the film, and λ is the wavelength of the incident beam.

According to Snellius law, birefringence as a function of the direction of the incident beam is defined as:

Δn = sinΘ/sinΨ

where sinΘ is the angle of incidence or the inclination angle of the optical axis of the film, and sinΨ is the corresponding angle of reflection.

Based on this law, the birefringence and corresponding optical retardation depend on the thickness of the film and the angle of inclination of the optical axis of the film (see Berek interferometer). Thus, the skilled practitioner knows that various optical retardations or various birefringent ink formulations can be induced by adjusting the thickness of the polymer film.

The birefringence (Δn) of the polymer film according to the invention is preferably in the range from 0.01 to 0.30, more preferably in the range from 0.01 to 0.25, even more preferably in the range from 0.01 to 0.16.

The optical retardation as a function of the thickness of the polymer film according to the invention is less than 200 nm, preferably less than 180 nm and even more preferably less than 160 nm.

In addition, the polymer films of the present invention can be used as alignment films of other liquid crystal or RM materials. For example, it can be used in LCDs to induce or improve the alignment of a switchable liquid crystal medium or to align a subsequent layer of a polymeric LC material coated thereon. In this way, a stack of polymerized LC films can be prepared.

In summary, the polymer films according to the invention are useful in optical components, such as polarizers, compensators, alignment layers, circular polarizers or color filters of liquid crystal displays or projection systems, and in particular in reflective films in which the reflective color varies spatially.

Accordingly, the present invention also relates to an optical component comprising at least one polymer film obtainable or obtained from the ink formulations described above and below.

In another preferred embodiment, the optical component is at least one obtainable or obtained from the ink formulations described above and below, selected from A plate, C plate, biaxial polymer film, cholesteric polymer film or even any combination thereof. , preferably at least two polymer films.

Preferably, the present invention relates to a color filter comprising at least one, preferably at least two polymer films obtainable or obtained from the ink formulations described above and below.

Preferably the color filter comprises a multicolor pixel pattern having a specific retardation, a polymer film on a multicolor pixel pattern obtainable from an ink formulation, provided by inkjet printing corresponding to each retardation of said multicolor pixel pattern, wherein said liquid crystal phase the transfer layer comprises a plurality of liquid crystal phase transfer regions corresponding to the multicolor pattern; the plurality of liquid crystal phase shifting regions have a delay correcting delay of the multicolor pixel pattern; The sum of the delay of the multi-color pixel pattern and the delay of the corresponding plurality of polymer film moving regions is characteristic and essentially equal for each pixel.

For this purpose, at least one, preferably at least two, obtainable or obtained from the ink formulations described above and below, in which the color filter has a variable birefringence for all subpixels of the color filter (eg red, green and blue). It is preferred to include a polymer film.

More preferably, the present invention relates to a quantum material-based color filter comprising at least one, preferably at least two polymer films obtainable or obtained from the ink formulations described above and below.

For this purpose, one or more, preferably two, of the color filters are obtainable or obtained from the ink formulations described above and below with varying reflective characteristics for every subpixel (eg red, green and blue) of the color filter. It is preferable to include the above cholesteric polymer film. For example, a red/green/blue CLC reflective device has both left-handed and right-handed orientations for each subpixel of the color filter.

The polymer film according to the invention can be used in displays of the transmission or reflection type. These include conventional or QD-type OLED and LCD displays comprising pixel-color-converter modules (PCC), in particular LCDs in DAP (deformation of aligned phase) or VA (vertical alignment) mode, for example ECB (electrically controlled Bending mode in birefringence), CSH (color super homeotropic), VAN or VAC (vertically aligned nematic or cholesteric) displays, MVA (multi-domain vertically aligned) or PVA (patterned vertical alignment) displays. or in hybrid types of displays, such as OCB (optically compensated bending cell or optically compensated birefringence), R-OCB (reflective OCB), HAN (hybrid aligned nematic) or pi-cell (π-cell) displays, TN (twisted) nematic), HTN (highly twisted nematic) or STN (super twisted nematic) mode display, AMD-TN (active matrix inductive TN) display, IPS (in-plane switching) mode (also as 'super TFT' display) known) can be used in the display. Particular preference is given to VA, MVA, PVA, OCB and pi-cell displays.

Accordingly, another aspect of the present invention relates to the use of at least one polymeric film or optical component described above and below in an optical device, or at least one polymeric film obtainable or obtained from at least one of the ink formulations described above and below. It relates to an optical device comprising.

Many of the compounds mentioned above and below and mixtures thereof are commercially available. All of these compounds are known or known per se, as described in the literature (e.g. in standard writings such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart). It can be prepared by a method described, more precisely, known or under reaction conditions suitable for the reaction. Also, variations known per se but not mentioned herein may be used.

It is understood that modifications may be made to the foregoing embodiments of the invention within the scope of the invention. Alternative features serving the same, equivalent or similar purpose may be substituted for each feature disclosed herein unless otherwise stated. Accordingly, unless otherwise stated, each feature disclosed is only one example of an equivalent or similar feature in the generic series.

All features disclosed herein may be combined in any combination, except combinations in which at least some of such features and/or steps are mutually exclusive. In particular, the preferred features of the present invention are applicable to all aspects of the present invention and may be used in any combination. Likewise, features listed as non-essential combinations can be used individually (not in combination).

It is understood that many of the features of the particularly preferred embodiments described above are inventive in their own right and not as part of the embodiments of the present invention. In addition to or alternatively to the presently claimed invention, you may be independently protected from these features.

The present invention will be explained in more detail with reference to the following working examples, which are merely illustrative and do not limit the scope of the present invention.

working example

Reactive mesogenic mixture (RMM) used

The following reactive mesogenic mixtures were prepared according to the table below:

RMM1:

RMM2:

RMM3:

Solvents and solvent systems used

used inkjet printer

general procedure

Ink formulations were prepared by mixing the corresponding RMM with the corresponding solvent system (SS). The ink was then printed with the indicated print dimensions (PD) and with the indicated drop spacing (DS). The layer was then annealed at 90° C. for 60 seconds and cooled to room temperature. The layer was then cured using a 250-450 nm Omnicure lamp at 50 mW for 120 seconds in air. Birefringence (Δn), and the central reflection wavelength (λ) and reflection bandwidth (dλ) for cholesteric polymer films were determined after curing.

working example

Non-cholesteric polymer films:

Cholesteric Polymer Film:

Claims (16)

10 to 50% by weight of at least one polymerizable liquid crystal compound; and
50 to 90% by weight of at least one organic solvent selected from the group consisting of aliphatic ketones, cyclic ketones, alkyl ethers of ethylene glycol or propylene glycol, alkyl esters of menthyl or aromatic solvents
Ink formulation for inkjet printing comprising a. According to claim 1,
An ink formulation, wherein at least one polymerizable liquid crystal compound is selected from direactive or polyreactive compounds of the formula DRM:

In the above formula,
P ¹ and P ² are independently of each other a polymerizable group,
Sp ¹ and Sp ² are independently of each other a spacer group or a single bond,
MG is a rod-shaped mesogenic group, which is preferably selected from the formula MG:

,
A ¹ and A ^2, in the case of multiple occurrences, independently of each other, are aromatic or cycloaliphatic groups, which optionally contain one or more heteroatoms selected from N, O and S, optionally mono- or polysubstituted ^{with L 1 ,}
L ¹ is P-Sp-, F, Cl, Br, I, -CN _{, -NO 2} , -NCO, -NCS, -OCN, -SCN, -C(=O)NR ⁰⁰ R ⁰⁰⁰ , -C(= O)OR ⁰⁰ , -C(=O)R ⁰⁰ , -NR ⁰⁰ R ⁰⁰⁰ , -OH, -SF ₅ , optionally substituted silyl, aryl or heteroaryl having 1 to 12 C atoms, or 1 to 12 straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having C atoms, wherein one or more H atoms are optionally replaced by F or Cl;
R ⁰⁰ and R ⁰⁰⁰ are independently of each other H or alkyl having 1 to 12 C atoms,
Z ¹ is independently of each other in case of multiple occurrences -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O-COO-, -CO -NR ⁰⁰ -, -NR ⁰⁰ -CO-, -NR ⁰⁰ -CO-NR ⁰⁰⁰ , -NR ⁰⁰ -CO-O-, -O-CO-NR ⁰⁰ -, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CH ₂ CH ₂ -, -(CH ₂ ) _n1 , -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CF ₂ CF ₂ -, -CH=N-, -N=CH-, -N=N-, -CH=CR ⁰⁰ -, -CY ¹ =CY ² - , -C≡C-, -CH=CH-COO-, -OCO-CH=CH- or a single bond,
Y ¹ and Y ² are each independently H, F, Cl or CN,
n is 1, 2, 3 or 4,
n1 is an integer from 1 to 10; 3. The method of claim 1 or 2,
An ink formulation, wherein the at least one polymerizable compound is selected from monoreactive liquid crystal compounds of the formula MRM:

In the above formula,
P ¹ , Sp ¹ and MG are as defined in the formula DRM of claim 2,
R is F, Cl, Br, I, -CN, _{-NO 2} , -NCO, -NCS, -OCN, -SCN, -C(=O)NR ^x R ^y , -C(=O)X, -C (=O)OR ^x , -C(=O)R ^y , -NR ^x R ^y , -OH, -SF ₅ , optionally substituted silyl, or straight chain or branched alkyl having 1 to 12 C atoms, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, wherein one or more H atoms are optionally substituted with F or Cl;
X is halogen, preferably F or Cl,
R ^x and R ^y are independently of each other H or alkyl having 1 to 12 C atoms. 4. The method according to any one of claims 1 to 3,
An ink formulation comprising one or more chiral additives. 5. The method according to any one of claims 1 to 4,
An ink formulation comprising one or more photoinitiators. At least 10 to 50% by weight of at least one polymerizable liquid crystal compound, 50 to 90% by weight of at least one selected from the group consisting of aliphatic ketones, cyclic ketones, alkyl ethers of ethylene glycol or propylene glycol, alkyl esters of menthyl or aromatic solvents A method for preparing an ink formulation comprising the step of mixing with a solvent. Use of an ink formulation according to any one of claims 1 to 5 in an inkjet printer. A polymer film obtainable or obtainable by inkjet printing an ink formulation according to any one of claims 1 to 5 onto a substrate and curing said ink formulation. A method for producing a polymer film comprising the steps of inkjet printing an ink formulation according to any one of claims 1 to 5 onto a substrate, and curing the ink formulation. Use of the polymer film of claim 8 as an optical film or in an optical component. An optical component comprising at least one polymer film of claim 8 . 12. The method of claim 11,
An optical component comprising at least one polymer film selected from an A plate, a C plate, a biaxial polymer film, a cholesteric polymer film, or any combination thereof. 13. The method of claim 11 or 12,
An optical component that is a color filter comprising at least one polymer film of claim 8 . 14. The method according to any one of claims 11 to 13,
An optical component that is a quantum material based color filter comprising at least one polymer film of claim 8 . Use of one or more optical components according to claim 11 in an optical device. An optical device comprising at least one optical component of claim 11 comprising at least one polymer film of claim 8 .